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3 Generations of Marantz flagship integrated amps measured
- Thread starter GXAlan
- Start date
restorer-john
Grand Contributor
The scale is just all out of whack. It's 60Hz, but two graduations up from 50Hz and 13 vertical graticules between 20Hz and 200Hz?! There should be 10.
Looks like 60Hz to me. Just click the mouse in the plot a little distance away from the peak, then drag the mouse to the peak while holding down the shift key -- it'll add an arrow with the actual frequency and amplitude of the peak to the plot.
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- Thread Starter
- #24
Got it. It does make sense that it is 60Hz hum and it is tricky since there are two divisions from 50Hz.
There is plenty of reading between the lines about how Marantz got Class D to sound good but there is a lot of commentary about environmental issues and the fact that the Sanken transistors in the PM-11s2 are not in production anymore. The PM-11s3 actually is supposed to measure worse than the PM-11s2 as well.
There is plenty of reading between the lines about how Marantz got Class D to sound good but there is a lot of commentary about environmental issues and the fact that the Sanken transistors in the PM-11s2 are not in production anymore. The PM-11s3 actually is supposed to measure worse than the PM-11s2 as well.
restorer-john
Grand Contributor
The major grid lines are as marked. Ignore anything in between them as these are auto-placed by the charting library. I just modified Multitone to remove these since I have no control over their placement or spacing.
Yes, cabling. And DAC to be isolated. Tuning the system is crucial. Balanced input topology is a must.
And also the scales of plots to be tuned, the plots are difficult to read. A lot of work
. It takes tens of hours.Not looking at some small system mistakes, one can see that the PM-11 is the best of the three, regarding spectrum cleanliness. NC modules are still the compromise, I came to this conclusion after months of testing them.
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- Thread Starter
- #32
It could be. I did some tests with a Korg DS-DAC-10R which is not instrument grade and it was already able to generate plenty of differences with different interconnects.
For the amp to load to ADC, they are long cables for convenience, and random lengths that I had lying around. The line level loopback is using Canare cable.
It seems that Multitone Analyzer is calculating THD in a wrong way - when signal fundamental is -13 dBFS down and the highest harmonics are around -136 dBFS, then THD should be around -119 dB, not -132 dB (for PM-10)...
This is because THD was calculated in dBFS in this case. The setting to compute it in dBr is available, but wasn't selected.
THD definition:
Total harmonic distortion - Wikipedia
It does not matter if the scale is in dBFS or dBr - THD is "relative to fundamental". Otherwise, it is misleading, when fundamental is not exactly at 0 dBFS.
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THD definition:
"The THD is usually expressed in percent or in dB relative to the fundamental as distortion attenuation."Total harmonic distortion - Wikipedia
en.wikipedia.org
It does not matter if the scale is in dBFS or dBr - THD is "relative tu fundamental". Othervise, it is misleading, when fundamental is not exactly at 0 dBFS.
The units are displayed on the plot, so there should be no confusion. I see the need for both, which is why I provided the setting.
"...no confusion..."
So, how do I know what THD is correct in the test results (it is the same signal measured):
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